In contemporary practice in office administration, even quite small entities (for-profit and non-profit) operate computerized calendar systems and phone-mail systems. A user will enter his (his or her being understood) appointments, meetings, time out of the office for personal matters such as vacation and doctor's appointments, etc. in his calendar. Other employees will be able to view the data in the calendar to find times when all of a group of people can attend a meeting. Meeting notices can be entered in the calendar selectively (when issued by co-workers) or automatically (e.g. when issued by management).
Telephone systems have recording facilities that permit a caller to leave a message on the computer that controls the telephone system (the computer can be located in an individual handset or in a “PBX” system).
It happens quite often that a calendar and phone-mail system will not be kept up to date; e.g. the phone-mail message states that someone is out of the office for weeks after he returns.
It would be advantageous for users of such systems if the data bases were automatically updated and reconciled to contain the same information.